Halide perovskite solar cells have attracted tremendous attention over recent years due to the rapid rise in solar cell efficiencies and their potential for providing high efficiency low cost solar power. Perovskite solar cell efficiencies have increased from 9% in 2012 to 21% in 2017 and are now competitive with traditional crystalline silicon cells. Despite this impressive rise in efficiency, the fundamental physics of these materials is not yet fully understood.The lifetime of the charge carriers plays an important role in determining the efficiency of the cell, as longer lived carriers will have a higher probability of reaching the electrodes. In efficient solar cells the charge carriers combine radiatively, which makes time-resolved photoluminescence spectroscopy a powerful tool to monitor the charge carrier lifetime and further the understanding of perovskite solar cells. In this application note time-resolved photoluminescence spectroscopy will be shown to be a powerful tool for investigating and optimising the behaviour of the perovskite solar cell material methyl ammonium lead iodide by measuring the influence of annealing on its charge carrier lifetime.

Normalised PL decays of three MAPI thin films that were annealed at 15, 30 and 60 minutes at 100 °C and measured using time-correlated single photon counting.